The present application relates to semiconductors, and more specifically, to techniques for forming semiconductor structures. Semiconductor structures may be formed with nanotips and other non-scale features. Recently, nanotips have attracted considerable interest because of distinctive differences in properties (e.g., electrical and optical properties) compared with bulk material. Nanotips are of increasing interest for numerous industries, due to potential for commercial application as, e.g., a field emission electron source, nanometer-cantilevers, nanoelectrodes, electrochemical electrodes, nanoscale tips for scanning probe microscopy such as scanning tunneling and atom force microscopy, etc. Arrays of nanotips also have many potential applications, e.g., as field emitter arrays in vacuum microelectronic devices, as gas-ionization sensors, etc.